Deflectable catheter constructed to inhibit component migration

ABSTRACT

A method of manufacturing a deflectable electrophysiological catheter includes constructing a shaft having a distal end and at least one lumen. The method further includes inserting a component into the lumen, and processing at least a portion of the distal end to reduce the cross-sectional profile of the lumen to capture/confine the component. A catheter manufactured using this method includes a shaft having at least one lumen. The lumen comprises a longitudinally-extending trough defined by a longitudinally-extending recess, within which a component is disposed, and a longitudinally extending open edge. The lumen further comprises a longitudinally-extending channel defined by a longitudinally-extending cavity and by the open edge of the trough. A planarity wire is disposed within the cavity and is configured to close the open edge of the trough to within a pre-defined tolerance that is less than the size of the component to retain the component in the recess.

BACKGROUND OF THE INVENTION

a. Field of the Invention

The present invention relates to electrophysiological (EP) catheters.More particularly, the present invention relates to a deflectable EPcatheter constructed to inhibit component migration.

b. Background Art

It is known to use catheters to perform a variety of functions relatingto diagnostic and therapeutic medical procedures. EP catheters findparticular application in cardiac electrophysiology studies andprocedures, such as various cardiac diagnostic and/or ablationprocedures. In such studies/procedures, electrical signals from theheart may be conducted through electrodes disposed at the distal end ofthe catheter to monitoring and recording devices associated with thecatheter. The electrodes may also be used for other purposes such asdelivering energy to the heart as stimulus to monitor the heart'sresponse thereto or to ablate a site of cardiac tissue that causes, forexample, an arrhythmia or abnormality in the heart rhythm.

To optimize the performance of a catheter, it is important that thedistal end of the catheter can deflect in one or more directions. Thisdeflection allows for the optimal positioning of the electrodes toperform their respective function. In conventional systems, a handleportion is provided at the proximal end of the catheter. The handleportion may include an actuator that is coupled to one or more pullwires that extend to a point at or near the distal end of the catheter.The combination of the actuator and the pull wire(s) serves toselectively effectuate movement of the catheter's distal end when theactuator is selectively manipulated. It is known that the pull wires ofthese systems may be disposed within a lumen or lumens in the shaftportion of the catheter along with various other components, such as,for example, the wires connected to the electrodes.

These conventional arrangements, however, are not without theirdrawbacks. One particular drawback lies in the configuration of thelumen relative to the components disposed therein. For instance, in anarrangement wherein a plurality of electrode wires, one or more pullwires, and a flat wire (e.g., a planarity wire) are disposed within onelumen, one or more of the electrode wires may migrate into contact witha pull wire or the planarity wire and become pinched between the innerwall of the lumen and the pull wire or planarity wire. Once the wire ispinched, it cannot move as the catheter is deflected. Consequently, thewire may break, thereby disabling the functionality of the electrodethat connects to the broken wire.

Accordingly, there is a need for a catheter and method of manufacturingthe same that will minimize and/or eliminate one or more of theabove-identified deficiencies.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a deflectable EP catheter and amethod of manufacturing the same. The catheter according to the presentteachings includes a shaft having a proximal end and a distal end, andat least one lumen disposed within the shaft. The at least one lumen hasa predetermined cross-sectional shape, and comprises at least onelongitudinally-extending trough defined by a longitudinally-extendingrecess and by a longitudinally-extending open edge. The at least onelumen further comprises a longitudinally-extending channel that isdefined by a longitudinally-extending cavity and by the open edge of thetrough. The catheter still further includes a component disposed withinthe longitudinally-extending recess of the trough, and a planarity wirethat is configured to close the longitudinally-extending open edge ofthe trough to within a pre-defined tolerance that is less than the sizeof the component so as to retain the component within thelongitudinally-extending recess.

The method of manufacturing an EP catheter according to the presentteachings includes constructing a shaft having a proximal end, a distalend, and at least one lumen disposed within the shaft. The methodfurther includes inserting a component within the lumen, and processingat least a portion of the shaft such that the cross-sectional profile ofthe lumen is reduced to capture/confine the component.

A further embodiment of the method according to the present teachingsincludes constructing a shaft having a proximal end, a distal end, andat least one lumen disposed within the shaft. In this embodiment, theconstructing step includes constructing the distal end to have a firstportion and a second portion. The first portion has a first outerdiameter, and at least one region of the second portion has a secondouter diameter that is greater than the first outer diameter. As withthe embodiment described above, this embodiment of the method furtherincludes inserting a component in the lumen. The method still furtherincludes processing at least the regions of the second portion of thedistal end that have the enlarged second diameter such that thecross-sectional profile of the lumen is reduced to capture/confine thecomponent disposed therein. This process causes the second outerdiameter to become substantially equal to the first outer diameter.

The foregoing and other aspects, features, details, utilities, andadvantages of the present invention will be apparent from reading thefollowing description and claims, and from reviewing the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a deflectable catheter in accordancewith the present teachings.

FIG. 2 is an enlarged view of the distal end of the catheter illustratedin FIG. 1.

FIG. 3 is an enlarged view of an alternate embodiment of the distal endof the catheter illustrated in FIG. 1

FIG. 4 is a cross-sectional view of the distal end of the catheterillustrated in FIGS. 1 and 2 taken substantially along the lines 4-4 inFIG. 2 before a process is performed on the distal end to reduce thecross-sectional profile of the lumen therein.

FIG. 5 is a cross-sectional view of the distal end of the catheterillustrated in FIGS. 1 and 2 taken substantially along the lines 5-5 inFIG. 2 following the performance of a process on the distal end in whichthe cross-sectional profile of the lumen is reduced.

FIG. 6 is a cross-sectional view of an alternate embodiment of thecatheter illustrated in FIGS. 1, 2, and 4 wherein the catheter is amulti-luminal catheter.

FIG. 7 is a flow diagram of a method of manufacturing the catheterillustrated in FIGS. 1-6.

FIG. 8 is a partial cross-sectional and perspective view of the catheterillustrated in FIGS. 1, 2, 4, and 6 taken substantially along line 8-8in FIG. 6.

FIG. 9 is a partial cross-sectional and perspective view of the catheterillustrated in FIGS. 1, 2, 4, and 6 taken substantially along line 9-9in FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein like reference numerals are usedto identify identical components in the various views, FIG. 1illustrates one exemplary embodiment of a deflectableelectrophysiological catheter 10. In its most general form, the catheter10 includes a handle portion 12 and an elongated shaft portion 14,wherein shaft 14 extends along an axis and includes a proximal end 15and a distal end 16. The catheter 10 may be used in a number ofdiagnostic and therapeutic applications, such as the recording ofelectrograms in the heart, the performance of a cardiac ablationprocedure, and other similar applications/procedures. Accordingly, oneof ordinary skill in the art will recognize and appreciate that theinventive catheter and method of manufacturing the same can be used inany number of diagnostic and therapeutic applications.

With continued reference to FIG. 1, the handle 12 is coupled to theshaft 14 at the proximal end 15. The handle 12 is operative to, amongother things, effect movement (i.e., deflection) of the distal end 16.As will be described in greater detail below, the handle 12 includes anactuator 17 that can be selectively manipulated to cause distal end 16to deflect in one or more directions (e.g., up, down, left, and right).

The catheter 10, and the shaft 14, in particular, further includes atleast one lumen 18 (shown in FIGS. 4-6, for example). The lumen 18extends longitudinally along an axial portion of the shaft 14 from theproximal end 15 to the distal end 16 and is formed to have apredetermined cross-sectional profile and size. It should be noted thatdepending upon the intended application of the catheter 10, the lumen 18may extend the entire length of the shaft 14 or may extend less than theentire length. Additionally, the catheter 10 may include more than onelumen in the shaft 14 (see, for example, FIG. 6 wherein catheter 10 hastwo lumens, 18 ₁ and 18 ₂). Therefore, one of ordinary skill in the artwill recognize and appreciate that the shaft 14 may have one or morelumens and/or have lumen(s) of various lengths. In an exemplaryembodiment, the shaft 14 is constructed of a polymeric material, such aspolyurethane, nylon, various types of plastic materials such as thatoffered under the trademark PEBAX®, which is a registered trademark ofArkema France, or any other suitable material. Additionally, the shaft14 may be formed using any number of different manufacturing processesknown in the art including, without limitation, extrusion processes.

FIGS. 2 and 3 are enlarged views of the distal end 16, 16′,respectively. As shown in these figures, the catheter includes one ormore electrodes (such as, for example, ring electrodes 20) mounted on oraffixed to the shaft 14, 14′ along the distal end 16, 16′. In theseparticular embodiments, the active outer surface of each electrode 20 isconfigured for exposure to blood and/or tissue. The electrodes 20 may beassembled with the shaft 14, 14′ using any number of known processes.For instance, the electrodes 20 may be built into the shaft using areflow process. In such a process, the electrodes 20 are placed at theappropriate/desired locations on the shaft 14, 14′, and then the shaftis exposed to a heating process in which the electrodes 20 and the shaftbecome affixed or bonded together. As will be described below,sufficiently sized apertures are formed in the shaft proximate to eachelectrode 20 in order to allow for wires connected to the electrodes 20to be threaded into the lumen 18.

In addition to, or in place of, the electrode 20, the catheter 10 mayinclude a tip electrode 22 disposed at the extreme distal end 16, 16′.Tip electrode 22 may be configured for various functionality including,without limitation, that described above with respect to the electrodes20. The tip electrode 22 may be affixed to distal end 16, 16′ in anumber of ways. For instance, the tip electrode 22 may be bonded to theinner diameter of the shaft 14, 14′ (i.e., the wall of the lumen 18)using an epoxy material.

In an exemplary embodiment, protective trim (not shown) is used to coverthe transitions between the electrodes 20, 22 and the shaft 14, 14′. Theprotective trim, which may be comprised of an epoxy material or anyother suitable material, prevents sharp edges from being exposed andalso prevents the ingress of blood and other fluids into the shaft 14,14′, and the lumen 18, in particular.

FIGS. 4 and 5 are cross-sectional views of the shaft 14 of a singlelumen catheter, with FIG. 4 depicting the shaft 14 prior to a processbeing performed on at least a portion of the shaft 14 in which thecross-sectional profile of the lumen 18 is reduced, and FIG. 5 depictingthe shaft 14 following the performance of such a process. With continuedreference to FIGS. 4 and 5, and also FIGS. 6, 8, and 9, in an exemplaryembodiment, the lumen 18 comprises at least one longitudinally-extendingtrough 24 and a longitudinally-extending channel 26. The trough 24 isdefined by a longitudinally-extending recess 28 and alongitudinally-extending open edge 30. The channel 26, on the otherhand, is defined by a longitudinally-extending cavity 32 and the openedge 30 of the trough 24. In the exemplary embodiment illustrated inFIG. 4, the shaft 14 is constructed such that the lumen 18 has a“cross-shaped” or “t-shaped” cross-sectional profile. Thus, in thisparticular embodiment, lumen 18 comprises a pair of troughs 24 (24 ₁ and24 ₂), and the channel 26 is disposed between the troughs and defined,in part, by each of the open edges 30 (30 ₁, 30 ₂) of the respectivetroughs. It should be noted that while a “cross-shaped” profile isillustrated with particularity, the present invention is not so limited.Rather, those of ordinary skill in the art will recognize and appreciatethat the lumen 18 may have any number of cross-sectional profiles, suchas, for example, that of lumen 18 ₂ illustrated in FIG. 6, wherein lumen18 ₂ includes a single trough 24. Additionally, the lumen 18 may also beconstructed such that it does not have a unitary cross-sectional shapethroughout its length. Rather, different portions of the lumen 18 mayhave different cross-sectional profiles. In any event, the lumen 18 isconfigured such that various components required for performing theparticular functionality of the catheter 10 (e.g., recordingelectrograms, ablation, ultrasound, etc.) are disposed therein (such aselectrode wires, pull wires, shape wires, planarity wires, wiring fortemperature sensing elements, etc.).

As briefly described above, in an embodiment wherein the catheter 10includes one or more electrodes 20, 22 associated with the shaft 14,14′, each electrode 20, 22 includes at least one electrode or lead wire34. The wires 34 are typically pre-coated wires such that they areinsulated from each other and other components in the system. In theembodiment illustrated in FIGS. 4 and 5, the electrode wires 34 aredisposed within a first trough 24 ₁ of lumen 18, and more particularly,in the recess 28 ₁ of the trough 24 ₁. The trough 24 ₁ defines a firstregion of the lumen 18, and the open edge 30 ₁ of the trough 24 ₁ servesas an opening to this region. This opening is defined by a pair ofshoulders 36 ₁, 36 ₂ (See FIG. 5) disposed at either side thereof. Inthe case of an exemplary electrode 20, one end of wire 34 is connectedto the electrode 20 and the other end is threaded through acorresponding aperture (not shown) in the shaft 14, 14′ and into thelumen 18. The wire 34 extends through the lumen 18 and is connected to,for example, monitoring and/or recording devices associated with orconnected to the catheter 10. These devices are typically locatedproximate to the handle 12. In the case of the tip electrode 22, theshaft 14, 14′ may have an aperture therein configured to receive a wire34 that is connected to the tip electrode 22. In either case, one end ofthe wire 34 is connected to the electrode 22 and the other end isthreaded into the lumen 18 and connected to, for example, the monitoringor recording devices described above.

In addition to the electrode wires 34, other components may also bedisposed within the lumen 18. For instance, the handle 12, and theactuator 17 in particular, may comprise at least one pull wire 38operatively connected to it to facilitate deflection of the distal end16. As depicted in FIGS. 4 and 5, the pull wire 38 is disposed within asecond trough 24 ₂ of lumen 18, and more particularly, the recess 28 ₂of the trough 24 ₂. The second trough 24 ₂ defines a second region ofthe lumen 18, different from the first region in which the electrodewires 34 are disposed. The open edge 30 ₂ of the trough 24 ₂ serves asan opening to this second region, and this opening is defined by a pairof shoulders 40 ₁, 40 ₂ disposed at either side thereof. The pull wire38 may be surrounded by a liner 42 that serves the dual purpose ofproviding a lubricious surface to allow for the sliding of the pull wire38, while also insulating the pull wire 38 from electrical wires (e.g.,electrode wires 34) in the lumen 18. If provided, the liner 42 may beconstructed of a polymeric material, such as polytetrafluoroethylene(PTFE), or any other suitable material. It should be noted that thecatheter 10 is not limited to the single pull wire arrangementillustrated in FIGS. 4 and 5 and described above. Rather, the catheter10 may include two or more pull wires 38 disposed within the lumen 18 toenable the distal end 16 to deflect in two or more directions.

With continued reference to FIGS. 4 and 5, the catheter 10 may furtherinclude a planarity wire 44 disposed in the channel 26 of the lumen 18(and cavity 32 thereof, in particular). The channel 26 is locatedbetween the first and second troughs 24 ₁, 24 ₂, and therefore, betweenthe first and second regions of the lumen 18 (and the openings thereof,in particular), and electrode wires 34 and the pull wire 38. The channel26 defines a third region of the lumen 18 that is different from boththe first and second regions described above (i.e., those defined by thetroughs 24 ₁, 24 ₂). Accordingly, the lumen 18 defines an insertiontolerance between the surfaces of the planarity wire 44 and thecorresponding regions of the lumen 18 to allow for the planarity wire 44to be inserted therein. In the illustrated embodiment, the planaritywire 44 has opposing flat surfaces 46 ₁, 46 ₂ and serves to maintain theplanarity of the shaft 14 as the shaft 14 deflects. As with the pullwire 38, the planarity wire 44 may also include a liner 48 similar tothe liner 42 that serves the same purpose(s) as the liner 42. If thecatheter 10 includes more than one pull wire 38, the additional pullwires would be disposed at the various sides of the planarity wire 44 sothat the planarity wire 44 may maintain planarity of the shaft 14regardless of the direction of deflection.

It should be noted that while the embodiment described above includescomponents that may be primarily used for diagnostic applications,components for therapeutic applications can also be disposed within thelumen 18. Accordingly, to the extent not encompassed by the descriptionabove, components used in ablation procedures, ultrasound procedures,and the like may also be disposed within the lumen 18.

Additionally, it should be further noted that the catheter 10 is notlimited to a single lumen arrangement. For instance, FIG. 6 illustratesa multi-luminal catheter 10′ wherein two or more lumens 18 ₁, 18 ₂, . .. 18 _(n) are disposed within the shaft 14″. In such an arrangement, thevarious components described above are disposed in respective lumens(the components are not shown in FIG. 6). In one particular embodiment,the lumen 18 ₁ may be used as an irrigation lumen, while the lumen 18 ₂,which, as briefly described above and as illustrated in FIGS. 6, 8, and9, includes a trough 24 and a channel 26, may contain some or all of thevarious components described above or additional components.Alternatively, some of the components (e.g., pull wires, electrodewires, shape wires, planarity wires, etc.) may be disposed in the lumen18 ₁, while others may be disposed in the lumen 18 ₂. Accordingly, thoseof ordinary skill in the art will recognize and appreciate that thecatheter 10 may have one or more lumens 18.

For ease of description purposes only, the remainder of the descriptionof the catheter 10 will be limited to a single-lumen arrangement. Itshould be noted, however, that both the foregoing and the followingdescriptions relating to the lumen or lumens 18 apply with equal forceto both single and multi-luminal arrangements. Accordingly, the presentinvention is not limited solely to the single lumen arrangementdescribed in detail above and below, but rather includes multi-luminalarrangements as well.

As described in the Background above, one disadvantage to thearrangement(s) depicted in FIGS. 4 and 6 is that there are gaps orspaces 50 between the various components disposed within the lumen 18.These gaps/spaces 50 are the result of the insertion tolerance requiredto allow for the insertion of the planarity wire 44 within the lumen 18,and provide a path for the electrode wires 34, for example, to migratefrom a first region of the lumen 18 (i.e., the trough 24 ₁, and therecess 28 ₁ thereof, in particular) and into another region of the lumen18 (i.e., the channel 26, and the cavity 32 thereof, in particular,within which the planarity wire 44 is disposed; or possibly the trough24 ₂, and the recess 28 ₂ thereof, in particular, within which the pullwire 38 is disposed). When the wires 34 move into these regions, theycan become pinched between the components in those regions and the innerwall of the lumen 18. Once pinched, the wires 34 may be prevented frommoving freely during deflection. Consequently, the wires 34 may break,thereby rendering one or more electrodes 20, 22 disabled.

In order to combat this undesirable occurrence, at least a portion ofthe shaft 14, and most likely a portion of the distal end 16 having oneor more electrodes 20 mounted thereon, is subjected to a process that,as will be described in greater detail below and as depicted in FIG. 5,causes the cross-sectional profile and total volume of the lumen 18 tobe greatly reduced so as to capture or confine the component(s) disposedwithin the lumen 18, thereby having the effect of trapping and possiblyencasing the components in a desired region of the lumen 18. Morespecifically, this process eliminates, or at least substantiallyreduces, the gaps/spaces 50. In an exemplary embodiment, this processcomprises a heat-treating process; however, other energy-deliveryprocesses exist (such as sonic, reflow, radio-frequency, andultra-violet processes, as well as other known methods of polymerbonding) and may be used. Therefore, the insertion tolerance between theplanarity wire 44 and a particular region of the lumen 18 (e.g., theregions defined by troughs 24 ₁ and 24 ₂) is reduced to a pre-definedclosure tolerance that is less than the size of the component disposedwithin the region/trough (e.g., the size of the electrode wires 34,and/or the pull wire 38), so as to retain the component within theparticular region/trough of the lumen 18. Accordingly, the migrationpaths of the components are eliminated, or at least substantiallyreduced; and, thus, the occurrence of component migration is inhibited.Additionally, because the flat surfaces 46 ₁, 46 ₂ of planarity wire 44are in close proximity to the shoulders 36 ₁, 36 ₂ and 40 ₁, 40 ₂ of theopenings of the first and second regions of the lumen 18 (e.g., troughs24 ₁, 24 ₂), respectively, the movement of the planarity wire 44 awayfrom the openings (i.e., the open edges 30 ₁, 30 ₂ of the troughs 24 ₁,24 ₂) is restricted. Thus, the planarity wire 44 is configured to closethe opening of the region/trough to within a pre-defined tolerance thatis less than the size of the component so as to confine or retain thecomponent within that region/trough, thereby further assisting with theelimination, or at least substantial reduction, of the migration pathsof the component.

In an exemplary embodiment, the shaft 14 is constructed of or comprisesa material that is sufficiently incompressible to prevent the componentsdisposed within the respective regions of the lumen 18 from compressingthe material so as to enlarge the closure tolerance of the lumen,thereby creating a migration path for the component. In other words, thematerial is such that when the catheter is deflected, the force exertedon an electrode wire and directed against the wall of lumen 18, forexample, would not be sufficient to displace the shaft material to suchan extent that the electrode wire would be able to slide through thereduced gaps or spaces created as a result of the process in which thecross section of the lumen is reduced.

The reduced lumen area profile prevents, or at least substantiallyreduces, significant lateral movement of the components, such as theelectrode wires 34, within the lumen 18, and, therefore, prevents, or atleast substantially reduces, the likelihood of one component migratinginto a region of the lumen 18 occupied by another component. Otheradvantages include, for example, the reduction in size of the aperturesin the shaft 14 through which electrode the wires 34 are threaded intothe lumen 18, and the prevention of fluid ingress into the lumen 18,which reduces the potential for electrical noise.

With reference to FIG. 7, a method of manufacturing the catheter 10 willnow be described. The exemplary method comprises a first step 52 thatincludes constructing the shaft portion 14. More particularly, step 52includes constructing the shaft portion 14 to have a proximal end 15configured for coupling with the handle 12, a distal end 16, and a lumen18 therein. Alternatively, the shaft 14 may be constructed to have morethan one lumen 18 therein so as to create a multi-luminal catheter. Thelumen 18 extends along at least an axial portion of the length of theshaft 14 between the proximal end 15 and the distal end 16 and has apredetermined cross-sectional profile. The cross-sectional profiledefines at least one longitudinally-extending trough 24 defined by alongitudinally-extending recess 28 and an longitudinally-extending openedge 30, and a longitudinally-extending channel 26 defined by alongitudinally-extending cavity 32 and the open edge 30 of the trough24. In an exemplary embodiment, constructing step 52 comprisesconstructing the shaft 14 using an extrusion process in which apolymeric material (e.g., polyurethane, PEBAX®, nylon, etc.) is extrudedto form the shaft 14. However, the present invention is not limited tosuch a process or material. Rather, those of ordinary skill in the artwill recognize and appreciate that other processes and materials (e.g.,various types of polymeric materials and/or thermoplastics) may besuitable to achieve the same result.

Regardless of the material and process used, the material and theprocess must be properly matched. As was briefly described above, and aswill be described again below, the material must have the capability tobe displaced or to shrink when subjected to a process, such as, forexample, a heating process, that is performed subsequent to theconstructing step. However, the constructing process must be carefullycontrolled so as to not generate or expose the shaft 14 to an excessiveamount of heat that would cause the shaft material to be reflowed orshrunk during the construction process itself. Accordingly, the materialmust be able to withstand exposure to any heat generated in theconstruction process such that the material is reflowed or shrunk in asubsequent process rather than in the shaft construction process.

In an exemplary embodiment, step 52 further includes constructing theshaft 14 with at least one electrode 20 and/or tip electrode 22 thereonas was described in greater detail above. Alternatively, the electrodes20, 22 are affixed to and/or mounted on the shaft 14 in a subsequentstep.

A second step 54 includes inserting at least one component into one ormore lumens 18 of the shaft 14. In an exemplary embodiment, thecomponents inserted and disposed within the lumen 18 include, asdescribed above, at least one electrode wire 34, at least one pull wire38, and/or a planarity wire 44. However, in other embodiments, thecomponents within the lumen 18 may take the form of any number ofdifferent or additional articles/devices typically present in cathetersused for diagnostic or therapeutic purposes (e.g., shape wires, wirescorresponding to temperature sensing elements, etc.). In the embodimentwherein the components include the electrode wire 34, the pull wire 38,and the planarity wire 44, each component is disposed within arespective region of lumen 18 (i.e., a respective trough 24 for each ofthe electrode wire 34 and the pull wire 38, and the channel 26 forplanarity wire 44), with the planarity wire region being located betweenthe electrode wire region and the pull wire region. Accordingly, theconstructing step 52 includes the substep of providing a lumen so as toestablish an insertion tolerance between the surfaces of a planaritywire and corresponding regions of the lumen to allow for the insertionof the planarity wire.

A third and final step 56 includes processing at least a portion of theshaft 14 such that, as described above, the cross-sectional profile ofthe lumen 18 is reduced so as to eliminate or at least substantiallyreduce the gaps between the respective regions of the lumen 18, and,therefore, reduce the potential migration paths of the electrode wires34, thereby capturing/confining the component(s) disposed within thelumen 18. Accordingly, the processing step 56 is operative to reduce theaforementioned insertion tolerance to a pre-defined closure tolerancewherein the closure tolerance is less than the size of the component(s)disposed within the lumen 18. In an exemplary embodiment, the processingstep 56 comprises a heating process and it is applied to the distal end16. The processing step 56 may further comprise a heating process thatincludes reflowing a portion of the shaft 14.

In an alternate exemplary embodiment depicted in, for example, FIG. 3,the constructing step 52 includes constructing a shaft 14′ to have afirst portion 58 having a first outer diameter 60 and a second portion62 wherein at least certain regions thereof have a second outer diameter64 that is larger than first diameter 60. Accordingly, the shaft 14′ isconstructed such that one or more regions (e.g., the regions betweenelectrodes 20, 22) of the second portion 62 contain more shaft materialthan first portion 58. In such an embodiment, the processing step 56comprises processing the second portion 62 such that as thecross-sectional profile of the lumen 18 is reduced, the material closestto the components and that comprises the inner wall of the lumen isdisplaced to create the reduced cross-sectional profile. As thismaterial is displaced, the void created by the displaced material isfilled with the extra material that forms enlarged regions of the secondportion 62 that have the enlarged second diameter 64. In such anembodiment, once the processing step 56 is complete, the outer diameter64 of second portion 62 is substantially the same as the outer diameter60 of first portion 58 (See FIG. 2). This ensures a smooth outer surfaceof shaft 14.

As briefly described above, the processing step 56 may include anynumber of energy-delivery processes, such as, for example,heat-treating, reflow, sonic, radio-frequency, ultraviolet, or other anyother suitable processes, or other known methods of polymer bonding,that are suitable for causing the cross-sectional profile of the lumen18 to be reduced, thereby capturing/confining the components therein.

In an alternate exemplary embodiment, an intervening step is performedprior to the processing step 56 that includes placing a shrink tube overthe portion of shaft 14 that is to be exposed to an energy deliveryprocess, for example, rather than having the shaft 14′ constructed toinclude the enlarged diametered regions. As energy is delivered andapplied during the processing step 56, the shrink tube constricts andmelts into the surface of the shaft 14. In this manner, the shrink tubemay serve to fill the voids in shaft 14 that were left by the reductionin the cross-sectional profile of the lumen 18.

An additional step, which may be performed after the shaft 14 isprocessed, or any time before, includes coupling the shaft 14 with thehandle 12. Those of ordinary skill in the art will recognize andappreciate that any number of coupling methods may be used to carry outthis step.

Although only certain embodiments of this invention have been describedabove with a certain degree of particularity, those skilled in the artcould make numerous alterations to the disclosed embodiments withoutdeparting from the scope of this invention. For example, other processmay be used to construct and assemble catheter 10. Further, varioustypes of energy-delivery processes may be employed to carry out theprocessing function described above. Still further, different types ofcatheters may be manufactured or result from the inventive processdescribed in detail above. For instance, catheters used for diagnosticpurposes and catheters used for therapeutic purposes may both bemanufactured using the inventive process. Additionally, all directionalreferences (e.g., upper, lower, upward, downward, left, right, leftward,rightward, top, bottom, above, below, vertical, horizontal, clockwise,and counterclockwise) are only used for identification purposes to aidthe reader's understanding of the present invention, and do not createlimitations, particularly as to the position, orientation, or use of theinvention. Joinder references (e.g., attached, coupled, connected, andthe like) are to be construed broadly and may include intermediatemembers between a connection of elements and relative movement betweenelements. As such, joinder references do not necessarily infer that twoelements are directly connected and in fixed relation to each other. Itis intended that all matter contained in the above description or shownin the accompanying drawings shall be interpreted as illustrative onlyand not limiting. Changes in detail or structure may be made withoutdeparting from the invention as defined in the appended claims.

1. A method of manufacturing a deflectable electrophysiologicalcatheter, the method comprising the steps of constructing a shaft havinga proximal end, a distal end, and a lumen having a cross-sectionalprofile; inserting a component within said lumen; and processing atleast a portion of said shaft such that the cross-sectional profile ofsaid lumen is reduced to confine said component.
 2. The method of claim1, wherein said constructing step further comprises providing said lumenso as to establish an insertion tolerance between surfaces of aplanarity wire and corresponding regions of said lumen to allow for theinsertion of said planarity wire; and said processing step furthercomprises reducing said insertion tolerance to a closure tolerance,wherein said closure tolerance is less than a size of said componentdisposed within said lumen.
 3. The method of claim 1, wherein saidconstructing step further comprises constructing a shaft having a firstportion with a first outer diameter and a second portion, wherein aregion of said second portion has a larger outer diameter than saidfirst outside diameter; and said processing step further comprisesprocessing said second portion such that when said cross-sectionalprofile is reduced, the material of said second portion is displaced andsaid larger outer diameter of said region of said second portion becomessubstantially equal to the first outer diameter of said first portion.4. The method of claim 1, wherein said processing step further comprisesemploying an energy delivery process.
 5. The method of claim 4, whereinsaid method further includes the step of placing a shrink tube over saidportion of said shaft prior to said processing step.
 6. The method ofclaim 1, wherein said constructing step comprises constructing saidshaft to have a plurality of lumens.
 7. The method of claim 1, whereinsaid constructing step includes constructing said shaft such that saidlumen has a cross-shaped cross-sectional profile.
 8. The method of claim1, wherein said inserting step further comprises inserting an electrodewire in said lumen.
 9. The method of claim 1, wherein said insertingstep further comprises inserting at least one electrode wire in a firstlongitudinally-extending trough of said lumen; and wherein said methodfurther comprises inserting a pull wire in a second longitudinallyextending-trough of said lumen, inserting a planarity wire in alongitudinally-extending channel of said lumen that is located betweensaid first and second longitudinally-extending troughs, and affixing anelectrode on said distal end of said shaft.
 10. A method ofmanufacturing a deflectable electrophysiological catheter, the methodcomprising the following steps: constructing a shaft having a proximalend, a distal end comprising a first portion having a first outerdiameter, and a second portion having a region with a second outerdiameter that is greater than said first outer diameter; and a lumencomprising a cross-sectional profile and extending along said distalend; inserting a component within said lumen; and processing said secondportion of said distal end such that said cross-sectional profile ofsaid lumen is reduced to confine said component, and said second outerdiameter of said region of said second portion becomes substantiallyequal to said first outer diameter of said first portion.
 11. The methodof claim 10, wherein said constructing step further comprises providingsaid lumen so as to establish an insertion tolerance between surfaces ofa planarity wire and corresponding regions of said lumen to allow forthe insertion of said planarity wire; and said processing step isoperative to reduce said insertion tolerance to a closure tolerance,wherein said closure tolerance is less than a size of said componentdisposed within said lumen.
 12. The method of claim 10, wherein saidprocessing step comprises employing an energy delivery process.
 13. Themethod of claim 12 further comprising the step of placing a shrink tubeover said second portion of said shaft prior to said processing step.14. The method of claim 10, wherein said constructing step furthercomprises constructing said shaft to have a plurality of lumens.
 15. Themethod of claim 10, wherein said constructing step further comprisesconstructing said shaft such that said lumen has a cross-shapedcross-sectional profile.
 16. The method of claim 10, wherein saidinserting step includes inserting an electrode wire within said lumen.17. The method of claim 10, where said constructing step furthercomprising affixing an electrode on said distal end of said shaft, andwherein said inserting step further comprises inserting an electrodewire in a first longitudinally-extending trough of said lumen; saidmethod further comprising inserting a pull wire in a secondlongitudinally-extending trough of said lumen, inserting a planaritywire in a longitudinally-extending channel of said lumen that is locatedbetween said first and second longitudinally-extending troughs; andaffixing an electrode on said distal end of said shaft.
 18. Adeflectable electrophysiological catheter comprising a shaft bodyextending along an axis; a lumen disposed within said shaft body andextending along an axial portion of said shaft body, said lumencomprising a longitudinally-extending trough defined by alongitudinally-extending recess and by a longitudinally-extending openedge; and a longitudinally-extending channel defined by alongitudinally-extending cavity and by said longitudinally-extendingopen edge; a component having a size and being disposed in saidlongitudinally-extending recess; and a planarity wire disposed in saidlongitudinally-extending cavity and configured to close saidlongitudinally-extending open edge to within a pre-defined tolerancethat is less than the size of said component so as to retain saidcomponent in said longitudinally-extending recess.
 19. The catheter ofclaim 18, wherein said shaft body is constructed of a material that issufficiently incompressible to prevent said component from compressingsaid material and migrating from said longitudinally-extending recess.20. The catheter of claim 18, wherein said longitudinally-extendingrecess in which said component is disposed is a first region and saidlongitudinally-extending open edge is a first opening of said firstregion and includes a first pair of shoulders, one disposed at each sideof said first opening; said lumen further includes a second regionhaving a second opening, and said second opening of said second regionincludes a second pair of shoulders, one disposed at each side of saidsecond opening; and said planarity wire has opposing flat sides and isdisposed between said first and second pairs of shoulders, such thateach of said flat sides of said planarity wire is in close proximity tosaid respective pair of shoulders so as to restrict the movement of saidplanarity wire away from said first and second openings.